Nicolas Leoz speaks during a news conference in Asuncion April 23, 2013.Jorge Adorno

ASUNCION (Reuters) - The United States has sent Paraguay an extradition request for Nicolás Leoz, the former president of South America's soccer confederation, who was arrested on suspicion of racketeering in a corruption probe, Paraguay's Foreign Ministry said on Thursday.

Leoz, 86, has been under house arrest since June 1 after he and 13 other international soccer officials and sports media and marketing executives, including several from soccer's governing body FIFA, were hit with U.S. charges involving more than $150 million in bribes.

"We have received the documentation from the U.S. Embassy and have forwarded it to the Supreme Court," Juana Núñez, the ministry's liaison with Paraguay's justice system, told Reuters.

An attorney for Leoz previously said that his client was innocent and that he had been surprised by the charges.

"There is no deadline by which the court must decide on the request," Núñez said.

More than 100 countries, including Paraguay, Argentina and Trinidad, which all have nationals caught up in the probe, have extradition treaties with the United States.

FIFA has pledged to clean itself up in response to the worst crisis its 111-year history.

The agreement with Paraguay calls for each country to extradite defendants who have been charged with acts that constitute a crime in both nations and carry a minimum penalty of one year in prison.

Legal experts in Paraguay have said securing Leoz's extradition could be entail a lengthy process, citing potential appeals that could go as high as the country's Supreme Court.

"I know of extradition procedures that have been drawn out for long periods of time," Leoz's lawyer, Ricardo Preda, told Reuters. "The process is not very clearly defined."

Leoz ran CONMBEBOL for 27 years until stepping down in 2013, citing poor health. He has been held under house arrest in a wealthy suburb of Asuncion.

Last month Paraguay's president signed a new law stripping CONMEBOL's headquarters of its immunity, paving the way for possible police raids on the complex.

The quasi-diplomatic status was granted to the sprawling 98-acre (40-hectare) complex in 1997 and had prevented authorities from conducting searches of it.